How to Map Timestamp to SCN or Vice Versa
If you are trying to do an incomplete recovery (also called Point-In-Time Recovery, PITR), you may want to know a System Change Number (SCN) using… Read More »How to Map Timestamp to SCN or Vice Versa
How to Check Current System Change Number (SCN)
System Change Number Some DBAs will schedule a cron job to capture System Change Number (SCN) periodically to save as a Timestamp/SCN mapping reference. To… Read More »How to Check Current System Change Number (SCN)
How to Resolve ORA-19809 Limit Exceeded for Recovery Files
ORA-19809 We usually watch the space usage of log archive destination very closely because the database will be suspended if the space is full. Particularly,… Read More »How to Resolve ORA-19809 Limit Exceeded for Recovery Files
How to Implement Transparent Application Failover (TAF) by Local Naming
Transparent Application Failover (TAF) Besides Connect-Time Failover by local naming, there is a function called Transparent Application Failover (TAF) can do Run-Time Failover to enable… Read More »How to Implement Transparent Application Failover (TAF) by Local Naming
ANALYZE vs DBMS_STATS
Oracle recommends to use DBMS_STATS instead of ANALYZE since 8i. Sometimes, we might get confused by the two similar tools. So I took some times… Read More »ANALYZE vs DBMS_STATS
How to Resolve ORA-30036 UNABLE TO EXTEND SEGMENT BY 8 IN UNDO TABLESPACE 'UNDOTBS1'
ORA-30036 This error ORA-30036 could be very serious in a situation that is described below and may make users panic: One day, a DBA was… Read More »How to Resolve ORA-30036 UNABLE TO EXTEND SEGMENT BY 8 IN UNDO TABLESPACE 'UNDOTBS1'
How to Resolve ORA-01653 Unable to Extend Table in Tablespace
ORA-01653 The following two error messages are very similar. As a DBA, you'll probably meet them someday in the future. ORA-01653 is for table, ORA-01654… Read More »How to Resolve ORA-01653 Unable to Extend Table in Tablespace
How to Remove No-Name or Empty-Name Files
After you finish your shell scripting, you'd like to try your scripts to see the result in your test environment. In the debug phase, you… Read More »How to Remove No-Name or Empty-Name Files
How to Resolve Only at Command is Available to Schedule Jobs
Only at Command Available When you are a customer DBA at your client's site to do routine db data collection or planned health check tasks,… Read More »How to Resolve Only at Command is Available to Schedule Jobs
How to Find Most Expensive SQL
With a demanding database, you may want to know how to find out the most expensive sqls. Running on Oracle, we have Cost-Based Optimizer, the… Read More »How to Find Most Expensive SQL